Remove SurfaceSequence from mus client code.

services/ui/ws/window_server.h

Index: services/ui/ws/window_server.h
diff --git a/services/ui/ws/window_server.h b/services/ui/ws/window_server.h
index c9c3c47946efb7e9aca37bcb80259d00d3a1f84e..01e3e5f3114c8c3c2a7917e6ccc08152d6f02ddf 100644
--- a/services/ui/ws/window_server.h
+++ b/services/ui/ws/window_server.h
@@ -192,12 +192,6 @@ class WindowServer : public ServerWindowDelegate,
   void ProcessWindowDeleted(ServerWindow* window);
   void ProcessWillChangeWindowPredefinedCursor(ServerWindow* window,
                                                mojom::Cursor cursor_id);
-  void ProcessWindowSurfaceCreated(
-      ServerWindow* window,
-      mojom::CompositorFrameSinkType compositor_frame_sink_type,
-      const cc::SurfaceId& surface_id,
-      const gfx::Size& frame_size,
-      float device_scale_factor);
 
   // Sends an |event| to all WindowTrees belonging to |user_id| that might be
   // observing events. Skips |ignore_tree| if it is non-null. |target_window| is